Process systems or process devices of semiconductor technology are generally of modular structure. They conventionally consist of different chambers in which various process steps are carried out. Thus, for example for pretreatment of wafers, process steps such as wet cleaning, plasma treatment, etching or heating can be used, while for primary treatment of a wafer, bonding, lacquering, imprinting, embossing and exposure are possible. In known process systems the wafers or wafer stacks are transported with cassettes between the process systems or modules of process systems.
During transport, the contamination, damage, fouling or oxidation and thus influencing of other process steps can occur.
Contamination of the primary treatment chambers between treatments of successive wafers, therefore in loading and unloading of wafers, is also a problem.
Furthermore it is critical with respect to time that in the primary treatment large pressure differences from atmospheric pressure as far as very low pressures of 10−6 bar or less must be overcome.